From "The Rapids" to "Port Sarnia" to "Sarnia", the city has undergone many changes - from an Indian hunting ground to an up-and-coming settlement and an industrial centre. In 1812, Sir John Colborne was appointed Governor of the Isle of Guernsey, one of the Channel Islands. In 1829, the area and Townships of Sarnia and Moore were surveyed by Boswell Mount, and named by Sir John Colborne. Previously thought to be the Roman name for the Isle of Guernsey, it has now been found that the name Sarnia has a Celtic origin.

In 1835, Colborne paid his first visit to what is now the city of Sarnia, then known as "The Rapids". Previous to his visit, the villagers had decided that a change of name was necessary, but found it impossible to agree on a new name. The English settlers favoured the name "Buenos Aires" and the Scottish, "New Glasgow". To break the deadlock, Sir John Colborne suggested "Port Sarnia" and on January 4 1836, the name was formally adopted by a vote of 26 to 16.

A year previous to the adoption of the name Port Sarnia, the village was composed of 44 taxpayers, 9 frame houses, 4 log houses, 2 brick dwellings, 2 taverns and 3 stores. An Act to incorporate the Town of Sarnia was assented to on June 19 1856. The name Port Sarnia was officially changed to "The Town of Sarnia" effective January 1 1857. The population of the Town was mentioned in the Act at upwards of 1,000 inhabitants and there were three wards.

An Act to Incorporate the City of Sarnia was assented to on April 20 1914. The name Town of Sarnia would be officially changed to "The Corporation of the City of Sarnia" effective May 7 1914. This day was marked by the visit of Canada’s Governor General, H.R.H. the Duke of Connaught, and his daughter Princess Patricia. It was also on this day that Sarnia adopted the title of "The Imperial City". The population of the City was mentioned at 10,985 in the Act, and there were six wards.